The Rome theater was scrambling Monday to find replacements for the Italian maestro, who for the last six years has served as its honorary lifetime director.

Muti had been set to conduct Verdi's "Aida," starting Nov. 27, and Mozart's "Le Nozze di Figaro," in spring 2015. Past performances conducted by Muti sold out, boosting both the theater's prestige and coffers in a country where opera is dominated by Milan's La Scala.

Opera house General Manager Carlo Fuortes announced "with very great regret" that Muti was backing out of this season's commitments, which run from this fall through next spring. He quoted Muti as concluding in a letter after "long and tormented reflection" that there just aren't the conditions "to guarantee that serenity which for me is necessary for the success of the performances."

The theater has bounced back from a 12-million-euro ($16 million) shortfall to balance its books. But this summer, musician strikes marred the theater's season, popular among tourists, amid the ancient ruins of Caracalla's Theater. At one performance, a sole pianist provided music instead of an orchestra.

Fuortes and Rome Mayor Ignazio Marino said in a statement that Muti was "undoubtedly influenced" by "continual protests, internal conflicts and strikes that have lasted months" causing several performance cancellations.

They expressed hope Muti would eventually return. Union leaders also urged him to change his mind.

Muti, who is music director of the Chicago Symphony Orchestra, told Teatro dell'Opera that he wanted to dedicate himself in Italy to the Cherubini youth orchestra he founded.

The maestro is familiar with discordant notes of musician disputes. He resigned in 2005 from La Scala after a labor dispute wrote the coda to his nearly two decades there.